6.5 Inch Subwoofers in rear sail panels?

[mabbasest]

Hi Guys,
I'm installing some hertz mille pro mpk 163.3 speakers in the front (dash midrange, tweeter sail panel) and and an audison prima set in the back (already came with the car), but this got me wondering. Since the rear is mainly going to be used for fill, and I can get the Hertz to relatively comfortably get down to 70hz, I may be able to put some 6.5in subwoofers in the rear panels. Is this a stupid idea? What's the internal volume of the rear panel speaker enclosure, and how leaky is it?

[1.4_tsi]

I don't know whether my wide angle photo helps at all. From memory, I would guess approaching a couple litres in each speaker mount with more in the cavities behind:

Interior rear removed.jpg

[mabbasest]

Thanks for that picture. That gives me a much better idea. I think with some blood sweat and tears I could fit 6.5 inch subs in there for the 40-70/80hz region, make it airtight, and maybe add some coaxials/full-range drivers for some rear fill. God I still have so much sound deadening left over to do.

[1.4_tsi]

Take care when pulling the side panels off - the area over the B pillar is prone to splitting at the seam or cracking - one of the legacies I inherited from previous Motability adaptations on mine